At present, double-layer spectacles formed by mounting auxiliary spectacles on spectacle frames with bottom spectacle lenses are available in the market, with the auxiliary spectacles mounted to the bottom spectacles through magnets or through a concave convex mechanism. Conventional spectacles and auxiliary spectacles are sold in sets, and one kind of auxiliary spectacles can only fit with one kind of bottom spectacles, which leads to complicated structures, low interchangeability, inconvenient usage and troublesome carriage.